This article has a correction. Please see:

Closing the door to cancer cells

Breast cancer is one of the most common tumor types, and metastasis greatly increases the risk of death from this disease. By studying the process of intravasation or entry of cells into the vasculature, Karagiannis et al. discovered that, in addition to killing tumor cells, chemotherapy treatment can also increase intravasation. Groups of cells collectively known as tumor microenvironment of metastasis (TMEM) can serve as gateways for tumor cells entering the vasculature, and the authors discovered that several types of chemotherapy can increase the amounts of TMEM complexes and circulating tumor cells in the bloodstream. The researchers also determined that a drug called rebastinib can interfere with TMEM activity and help overcome the increased risk of cancer cell dissemination.